Skimming collects the highest version of every rule in the ruleset and copies the rules to a new major or minor version of that ruleset on the same system. Rule availability and the type of skimming determine which rules the system carries to a higher ruleset version.

You can select between a major skim and a minor skim. The skim type corresponds with the digits in a ruleset version number. The two first digits define the major version, and the two middle digits define the minor version. For example, in the ruleset version 06-09-10, 06 indicates the major version, and 09 corresponds with the minor version. The major ruleset version typically specifies a release of your application or other significant changes, while the minor version relates to an enhancement or a less extensive change in your application. When you select a skim type, consider changes that you want to merge in the higher ruleset version. The final two digits correspond with patch releases and do not have a separate skim type associated with them. Skimming copies rules so that all your rules in lower ruleset versions remain unchanged. During skimming, the system omits rules in the major versions that are lower than the major version that you specify. For example, if you opt to skim 02-05-02 into 03-01-01, the system ignores any rules in the version 01-XX-XX.

The following table displays which rules you can include in a higher ruleset version by using either the major or minor skimming type:

The update history of the new skimmed rule contains only one instance that reflects the date and time of the rule creation based on the skim operation. The history of the source rule is available and remains unchanged.

For relevant learning materials, see an Application versioning module on Pega Academy.